<p> Bitrix Framework is supplied with a huge variety of perfectly tested, secure
and high-performance components ("News", "Menu",
"Sitemap" and hundreds of others). The standard components is a
simplest way to reduce the project development time and costs because all that
is to be done is to fit them to the project specifications.</p>

<p>However, there still may occur a situation when no existing component is
capable of performing a required function and a custom solution is to be
developed. When creating your custom components, use the standard ones as an
example of user interface, public section accessibility, performance and
security.</p>
<p>On a large scale, a web project can be envisaged as a set of web pages
containing standard and/or custom components.</p>

<ol>
<li>Make up a complete registry of components you use in the project, optionally
  grouping the components into two major lists: standard and custom.</li>
<li>The standard components always have a "bitrix:" prefix. Always
  check the user interface and the component settings in the public section.<p>For
  example, if a customized "bitrix:news" component is used to render
  the "Details" list, the component name and settings should reflect the
  purpose: for example, the "News per page" parameter should be
  hidden. </p>
</li> 
<li>Pay special attention to cache mode in each component. The recommended
  option is "Auto + Managed" with long cache lifetime. It is essential to
  remember that, if the caching is disabled, a component will perform database
  queries every time it needs data which will decrease the website performance.
<p><img height="96" border="0" width="486" src="/bitrix/images/main/checklist/en/QS0020.png" /></p>
</li> 
<li>Run system update. Once it has completed, verify that all the components are
  intact and function properly.</li>
 </ol>